A count of robotics publications in the medical literature reveals that the impact of medical robotics has exponentially grown since its inception in late 1980s. Robots do not only augment physician's manipulation capabilities, but also establish a digital platform for integrating medical information [R. H. Taylor and D. Stoianovici, “Medical robotics in cornputer-integrated surgery,” IEEE Transactions on Robotics and Automation, vol. 19, pp. 765-81, 2003; R. M. Satava, “The operating room of the future: observations and commentary,” Semin Laparosc Surg, vol. 10, pp. 99-105, 2003}. Medical imaging data, in particular, gives robots abilities unattainable to humans, because, unlike humans, robots and imagers are digital devices. Image-guided interventions (IGI) expand radiology practice above and beyond traditional diagnosis [F. A. Jolesz, “Neurosurgical suite of the future. II,” Neuroimaging Clin N Am, vol. 11, pp. 581-92, 2001], and do so with the use of modern tools.
IGI robotic systems, nevertheless, rely on the development of special imager interfaces, image registration, image-guided control algorithms, and also impose stringent requirements on the robotic hardware for imager compatibility, precision, sterility, safety, and nevertheless size and ergonomics. A robot's compatibility with a medical imager refers to the capability of the robot to safely operate within the confined space of the imager while performing its clinical function, without interfering with the functionality of the imager. This depends indeed on the type of intervention and imager used. There is provided in a study [D. Stoianovici, “Multi-Imager Compatible Actuation Principles in Surgical Robotics,” International Journal of Medical Robotics and Computer Assisted Surgery, vol. 1, pp. 86-100, 2005], a collection of a set of imager compatibility prescriptions from scientific papers and imager technical notes and assembled a global definition of Multi-Imager Compatibility. The study also derives a compatibility measure for individual imagers and, as expected, found the compatibility with Magnetic Resonance Imaging (to be most demanding.
On the other hand, the potential of MRI guided interventions is significant for the reason that MRI is the method of choice for imaging soft tissue, and, with spectroscopy, is the most advanced imaging modality for tumor detection [F. A. Jolesz, “Neurosurgical suite of the future. II,” Neuroimaging Clin N Am, vol. 11, pp. 581-92, 2001; J. Kurhanewicz, M. G. Swanson, S. J. Nelson, and D. B. Vigneron, “Combined magnetic resonance imaging and spectroscopic imaging approach to molecular imaging of prostate cancer,” J Magn Reson Imaging, vol. 16, pp. 451-63, 2002]. As such, the integration of robotics with MRI is highly significant for its prospective clinic outcome.
The design and construction of M compatible robots is a very challenging engineering task because most of the components commonly used in robotics can not be used in close proximity of the imager. MRI scanners use magnetic fields of very high density (up to several Tesla), with pulsed magnetic and radio frequency fields. Within the imager, ferromagnetic materials are exposed to very high magnetic interaction forces and heating can occur in conductive materials by electromagnetic induction. The use of electricity also can cause interference which can create image artifacts and/or robot signal distortions. As such, ideal materials for use with MRI are nonmagnetic and dielectric.
The problem becomes more intricate for robot actuation, where the ubiquitous electromagnetic motors are incompatible by principle when using MRI. MRI robotic research to date has commonly utilized piezoelectric (ultrasonic) motors [K Masamune, E. Kobayashi, Y. Masutani, M. Suzuki, T. Dohi, H. Iseki, and K Takakura, “Development of an MRI-compatible needle insertion manipulator for stereotactic neurosurgery,” J Image Guid Surg, vol. 1, pp. 242-8, 1995; K. Chinzei and K. Miller, “Towards MRI guided surgical manipulator,” Med Sci Monit, vol. 7, pp. 153-63, 2001; E. Hempel, H. Fischer, L. Gumb, T. Hohn, H. Krause, U. Voges, H. Breitwieser, B. Gutmann, J. Durke, M. Bock, and A. Melzer, “An MRI-compatible surgical robot for precise radiological interventions,” Comput Aided Surg, vol. 8, pp. 180-91, 2003; D. F. Louw, T. Fielding, P. B. McBeth, D. Gregoris, P. Newhook, and G. R. Sutherland, “Surgical robotics: a review and neurosurgical prototype development,” Neurosurgery, vol. 54, pp. 525-36; discussion 536-7, 2004]. These are magnetism free but use high-frequency electricity creating image distortion if operated closer than 0.5 m from the image isocenter. They also require deactivation during imaging.
Pneumatic actuation is a fundamentally flawless option for MRI compatibility. Pneumatics has been used in handheld drill-like MR instrumentation and tested in MR robotic end-effector designs [J. Neuerburg, G. Adam, A Bucker, K W. Zilkens, T. Schmitz-Rode, F. J. Katterbach, B. Klosterhalfen, E. Rasmussen, J. J. van Vaals, and R. W. Gunther, “MR-guided bone biopsy performed with a new coaxial drill system,” Rofo-Fortschr Rontg, vol. 169, pp. 515-520, 1998; E. Hempel, H. Fischer, L. Gumb, T. Hohn, H. Krause, U. Voges, H. Breitwieser, B. Gutmann, J. Durke, M. Bock, and A. Melzer, “An MRI-compatible surgical robot for precise radiological interventions,” Comput Aided Surg, vol. 8, pp. 180-91, 2003]. The major limitation of pneumatic actuators, however, has been their reduced precision in controlled motion [H. S. Choi, C. S. Han, K. Y. Lee, and S. H. Lee, “Development of hybrid robot for construction works with pneumatic actuator,” Automation in Construction, vol. 14, pp. 452-459, 2005].
While research on MRI compatible robotics has been quantitatively limited, there is a commercial IGI system. Early work [K. Chinzei, N. Hata, F. A. Jolesz, and R. Kikinis, “MR compatible surgical assist robot: System integration and preliminary feasibility study,” Medical Image Computing and Computer-Assisted Intervention—Miccai 2000, vol. 1935, pp. 921-930, 2000] was performed at the Brigham and Women's Hospital (BWH), Boston Mass. in collaboration with AIST-MITI, Japan. A robotic surgical assistant was constructed for open MRI presenting five degrees of freedom (DOF) with piezoelectric actuation. The manipulator is located at the top of the imager between the vertical coils of the MRI, and presents two long arms that extend to the imaging region to provide a guide for manual instrument manipulation [K. Chinzei and K Miller, “Towards MRI guided surgical manipulator,” Med Sci Monit, vol. 7, pp. 153-63, 2001]. Work continues with the development of a one-arm needle support and improved motion accuracy results were reported [Y. Koseki, N. Koyachi, T. Arai, and K. Chinzei, “Remote actuation mechanism for MR-compatible manipulator using leverage and parallelogram-workspace analysis, workspace control, and stiffness evaluation,” presented at Robotics and Automation, 2003. Proceedings. ICRA '03. IEEE International Conference on, 2003; Y. Koseki, R. Kikinis, F. A. Jolesz, and K Chinzei, “Precise evaluation of positioning repeatability of MR-compatible manipulator inside M,” Medical Image Computing and Computer-Assisted Intervention—Miccai 2004, Pt 2, Proceedings, vol. 3217, pp. 192-199, 2004].
An MRI compatible needle insertion manipulator was built at the Medical Precision Engineering lab of the University of Tokyo [K. Masamune, E. Kobayashi, Y. Masutani, M. Suzuki, T. Dohi, H. Iseki, and K. Takakura, “Development of an MRI-compatible needle insertion manipulator for stereotactic neurosurgery,” J Image Guid Surg, vol. 1, pp. 242-8, 1995]. The system was designed for neurosurgery applications and tested in-vitro. The same group has also designed a neurosurgical micro forceps manipulator [N. Miyata, E. Kobayashi, D. Kim, K. Masamune, I. Sakuma, N. Yahagi, T. Tsuji, H. Inada, T. Dohi, H. Iseki, and K. Takakura, “Micro-grasping forceps manipulator for MR-guided neurosurgery,” Medical Image Computing and Computer-Assisted Intervention-Miccai 2002, Pt 1, vol. 2488, pp. 107-113, 2002].
A research group from the University of Calgary, Canada also has reported their ongoing work and prototype specifications for the development of an MRI neurosurgical assistant with bilateral arms [D. F. Louw, T. Fielding, P. B. McBeth, D. Gregoris, P. Newhook, and G. R. Sutherland, “Surgical robotics: a review and neurosurgical prototype development,” Neurosurgery, vol. 54, pp. 525-36; discussion 536-7, 2004].
The Institute for Medical Engineering and Biophysics (IMB), Karlsruhe, Germany. also has reported several versions of a robotic system for breast lesions biopsy and therapy under MR guidance have been developed [W. A. Kaiser, H. Fischer, J. Vagner, and M. Selig, “Robotic system for biopsy and therapy of breast lesions in a high-field whole-body magnetic resonance tomography unit,” Invest Radiol, vol. 35, pp. 513-9, 2000; A. Felden, J. Vagner, A. Hinz, H. Fischer, S. O. Pfleiderer, J. R. Reichenbach, and W. A. Kaiser, “ROBITOM-robot for biopsy and therapy of the mamma,” Biomed Tech (Berl), vol. 47 Suppl 1 Pt 1, pp. 2-5, 2002]. These systems use piezoelectric motors located in a driving unit distal from the high-intensity magnetic field.
A system for general IGI under either computer tomography (CT) or MRI guidance also was developed by the IMB group, utilizing hybrid piezoelectric and pneumatic actuation [E. Hempel, H. Fischer, L. Gumb, T. Hohn, H. Krause, U. Voges, H. Breitwieser, B. Gutmann, J. Durke, M. Bock, and A. Melzer, “An MRI-compatible surgical robot for precise radiological interventions,” Comput Aided Surg, vol. 8, pp. 180-91, 2003]. This research led to the creation of a spin-off company, Innomedic (Herxheim, Germany, http://innomedic.com/). Innomedic's brochure states that the system is no robot because needle insertion is preformed manually, however, the described system embodies an actuated IGI device with at least 5 DOF of piezoelectric motors and/or pneumatic cylinders. There is no description presently publicly available of the details of such a system.
On the clinical application side, for needle access of the prostate gland under MRI guidance, manual procedures have been experimentally performed in a very few clinical trials, due to the complexity of the MR-IGI and the lack of proper instrumentation. [C. Menard, R. C. Susil, P. Choyke, G. S. Gustafson, W. Kammerer, H. Ning, R. W. Miller, K. L. Ullman, N. Sears Crouse, S. Smith, E. Lessard, J. Pouliot, V. Wright, E. McVeigh, C. N. Coleman, and K Camphausen, “MRI-guided HDR prostate brachytherapy in standard 1.5 T scanner,” Int J Radiat Oncol Biol Phys, vol. 59, pp. 1414-23, 2004]. Dr. Menard at the NIH (Bethesda, Md.) has investigated the feasibility of IGI for high dose prostate brachytherapy in a closed bore MRI scanner using a needle guide registered to the MRI. Similarly, Drs. D'Amico and Tempany at BWH have performed clinical trials for transperineal biopsy and seed brachytherapy on an open MRI scanner [N. Hata, M. Jinzaki, D. Kacher, R. Cormak, D. Gering, A. Nabavi, S. G. Silverman, A. V. D'Amico, R. Kilinis, F. A. Jolesz, and C. M. Tempany, “MR imaging-guided prostate biopsy with surgical navigation software: device validation and feasibility,” Radiology, vol. 220, pp. 263-8, 2001]. Finally, a passive needle guide packaged within a custom MR coil was tested on animal models [R. C. Susil, A. Krieger, J. A. Derbyshire, A. Tanacs, L. L. Whitcomb, G. Fichtinger, and E. Atalar, “System for MR image-guided prostate interventions: canine study,” Radiology, vol. 228, pp. 886-94, 2003] and is presently under clinical trials at the NIH for transrectal prostate biopsy.
It thus would be desirable to provide a new robot that is MRI compatible and preferably compatible for use with any of a number of devices embodying other imaging modalities (e.g., CT, X-ray, etc) and methods for use of such a robot in image guided interventions. It also would be desirable to provide devices, systems, apparatus and methods for automated delivery of a needle and also of brachytherapy seeds.